Copyright laws protect the creative works of authors, and restrict rights for limited periods of time. As more works take the form of computer files (i.e., in digital form), the act of copying has become easier. At the same time, the perfect nature of a digital copy does not provide a disincentive a user from using a copy.
Content providers attempt to overcome these difficulties with digital rights management. Digital rights management is a global term addressing techniques that protect a content provider's copyrights, while attempting to provide the user with the content in an appropriate fashion.
Typically, digital rights management techniques have attempted to prevent unauthorized copying with restrictions encoded in a file. Such techniques are generally sufficient to thwart the amateur, or unsophisticated, unauthorized copier, but most such techniques are at least susceptible to a hacking attack designed to break the restrictions. Few such techniques have proved successful for significant spans of time.
Thus, unauthorized copying is prevalent. However, proof of legitimate ownership is difficult to show in many instances, so the mere possession of a digital file can be seen as insufficient to prove ownership, since there is no way to tell if a particular instance of a file is authorized or unauthorized. For example, there is no way to determine if a particular instance of the file was “ripped” from a CD, or downloaded from a peer-to-peer network without authorization from the copyright holder.
Without the ability to prove ownership, prosecution of copyright infringers is implausible at best.
One prior solution to these problems is known as the DIVX® system. DIVX formatted products are distributed in a format only suitable for play on specially configured DIVX players. Upon playback of the file encoded on a DIVX medium, a play count for that medium is decremented. After the play count is decremented to zero, the DIVX media will no longer play on a DIVX player without securing additional “plays” or licenses from an issuer. However, the security features for DIVX are contained within the files, and therefore accessible to a hacking attack. A similar system, called Digital Video Express®, enabled rental of specially coded discs that did not require return. The Digital Video Express discs expired after a set, prepaid viewing period, such as 48 hours. Payment of an additional fee reauthorizes the Digital Video Express disc for another prepaid viewing period. However, like DIVX, Digital Video Express includes the protection in the file so that hackers have all the necessary information to crack the coding.
Another solution is a digital watermark encoded within a file. However, technology has arisen that allows copying of the digital watermark. Such copying reduces the value of the digital watermark.
It is therefore a challenge to develop a method to develop digital rights management strategies to overcome these, and other, disadvantages.